Train dispatching system for railroads



19361 F. BENEDICT TRAIN DISPATCHING SYSTEM FOR RAILROADS Filed March 8, 1928 2 Sheets-Sheet 1 ATTORNEY lNVENTOR Oct. 27, 1936." J E gcT I 2,058,554

TRAIN DISPATCHING SYSTEM FOR RAILROADS Filed March s, 1928 2 Sheets-Sheet 2 VNTOR 42%; BY

Patented Oct. 27, 1936 M E TATE TRAIN DISPATC'HING SYSTEM FOR .RAILROADS Frank Benedict, Rutherford,- N. J., assignor to General Railway Signal Company, Rochester;

Application'March s, 1923, Serial No. 260,178 16 Claims; (01. 2463-) This invention relates to train dispatching sysa code over the coding circuit simultaneously. In

terns of the wayside signal indicating type.

In a train dispatching system in which the movement of the train is dispatched through the is medium of semiautomatically controlled signals, located either in the cab or along the wayside, not only is it necessary to superimpose manual control upon these signals from a central point, such as a dispatchers oflice, but it is also necesu sary to indicate at the tower the location of trains along the track and their progress. It readily appears that if a single operator or dis-- patcher is to dispatch the movements of trains over an appreciable stretch of track, such as 100 miles, a large number of distinctive controls must be available to him, and further provision must be made for transmitting a large numberof distinctive OSindications. Ifhe present invention deals more particularly to control and indicating .means in which a large number of distinctive controls and a large number of distinctive indications may be transmitted over a single line circuit, In order to indicate the location and progress of trains it is proposed to indicate at the dispatchers office the condition of occupancy, of track circuits along the railway track. It is of course understood that not only is it possible for two or more track circuits to become occupied or unoccupied at exactly the same time, but this is something that is very likely to happen .and may even be a daily occurrence{ and since, in accordancewith the present invention, it is proposed to transmit distinctive signal indications by distinctive codes it is essential that two codes 35 should not be transmitted over the same linecircuit simultaneously, for if this were possible the resulting code might give a false indication, or constitute a jumbled code which would give no indication at all. f

40 With the foregoing and other important conxsider ations in mind it is proposed in accordance with the present invention to provide distinctive code responsive relays at both the dispatchers ofiice and at each way station, and to transmit distinctive codes from and to these various way stations to operate such code responsiverelays. More specifically, it is proposed to provide manually operable calling keys at the dispatchersoffice to operate the code responsive relays at the way 50 stations, to provide automaticallyoperated calling keys or code transmitters at thewaystations for transmitting'codes to the code responsive relays located in; the dispatchers office, and to provide suitable lockout means whereby it is impossible; for two code transmittersto transmit the specific embodiment of this lockout means it comprises a'normally de-energized lockout'circuit having lockoutrelays and secondary lockout relays associated therewith, the circuit arrangement being such that if a particular way station is to transmit a code to the dispatchers oflice the lookout circuit portion beyond that particular way station is cut off by opening the circuit at that point, and the portion of the lockout circuit between the dispatche'rfsoflice and this bar ticular way station is energized; provision being made to lock out a way station if the lock out circuit is energized from another way station. 7 Other objects, purposes and characteristic features of the present invention are in'part obvious from the accompanying drawings and will in part appear from the description hereinafter. i In describing the invention in detail references may be had to the accompanying single drawing contained on two separate sheets which may be laid end toen'd, and of which:- Fig. 1A shows conventionally the apparatus 10'- cated in the dispatchers ofiice, together with part of the trackway means; andf Fig. 1B shows a passing siding of a railway system, of which the switch' machines and signals are controlled by distinctive codes in accordance with the present invention, and in which the presence of a train on the detector track circuits K associated with this passing siding is indicated at the dispatchers ofl'lce in accordance with the present invention.

Apparatus at dispatchers office In the dispatchers office, convention-ally illustrated' by the rectangle D0, is preferably provided a suitable train dispatching machine having associatedtherewith a miniature track layoutof which the passing siding PS has been.

shown, this passing siding is to represent the passing siding PS of the railway system shown dicatorSQR? and G is a lever; L whereby-three,

different; calling keys RC C0 and ,NC may be operated, each of these calling keys transmitting. a distinctivecode if operated. The, lever L is directly connected to the cancelling-code calling key 09 whereby the cancelling code 5 the lever the normal code or the reverse code is transmitted, depending upon whether the lever is moved in the clockwise or the counterclockwise direction. When the lever is returned from one extreme position back to its normal neutral position, in which it is shown, the normal or reverse code key N0 or RC are not operated, but the cancelling code key 0C is operated, so that a cancelling code is transmitted. The normal code key N0 or the reverse code key R0 are not operated when the lever L is returned from the corresponding extreme position to the neutral position, because these keys are operated through the sectors I0, pinions ll, pawl l2 and ratchet tooth l3, and upon the return movement of the lever the pawl l2 merely disengages the tooth 13.

It readily appears that if the lever L is moved toward the right it may be moved a certain distance before it engages the projection l5 on the sector 10, after which the sector Hl moves with the lever L and rotates the pinion ll and in turn the ratchet tooth I3 in a counterclockwise direction carrying the normal code key NC with it, and that when the lever L has been moved to a point where the sector it! engages the stop 16 the normal code key' NC has been operated through exactly one revolution. If now, the lever L is returned to its intermediate or neutral position the sector In, pinion II and ratchet tooth l3 moves entirely without operating the normal code key N0 The reverse code key RC is operated in exactly the same way upon movement of the lever L in the counterclockwise direction and for this reason like parts have been assigned like reference characters, and for the same reason like parts for operating the keys RC CC and NC by the lever L have been designated by like reference characters.

For each lever in the dispatchers ofiice there are also provided two code responsive relays CRR, a red indicating relay RI and a green indicating relay GI, and the dispatchers oflice equipment also includes a repeater code relay RCR, a lookout relay LRS, a secondary lockout relay SLR and-a master relay MR. The exact purpose and function of these devices may readily be obtained from the operation of the system hereinafter described.

Way station apparatus In describing the way station apparatus itis deemed sumcient to describe the apparatus associated with the east end of the passing siding PS and for convenience the apparatus associated with the West end of this passing siding will be assigned like reference characters having distinctive exponents. This east end of the passing siding PS includes the usual track switch S which track switch may be operated by the power operated switch machine 5M lowing portion of the track switch S is provided with'the usualdetector track circuit including the track relay DT and the track battery 20, this detector track circuit being confined by the insulating'joints 2|. Although the wayside signals, which may be of anysuitable construction, but which have been conventionally shown as comprising semaphore signals, may be semiautomatically controlled and in accordance with trafiic' conditions in advance thereof in any suit The rolable Way as practiced in both double track and single track signaling, these signals are preferably controlled in a manner as shown in the application of S. N. Wight, Ser. No. 48,553 filed August 6,, 1925, or if light signals are used they are preferably controlled as shown in the application of S. N. Wight, Serial No. 120,423 filed July 3, 1926.

In the particular embodiment of the invention illustrated the entrance signal i, take siding signal I starting signal 2 and the dwarf starting signal 2' are controlled in accordance with the position of the track switch S either through switch box contact or contacts associated with the switch machine SM and the position of the normal relay NR and the reverse relay BB as more particularly described hereinafter. The starting signals 1 and I and the entering signals 8 and 8 at the west end of the passing siding PS are controlled in the same way. The normal relay NR and the reverse relay BB are controlled in accordance with distinctive codes transmitted to the code responsive relay ORR all as pointed out in the operation hereinafter.

In order to indicate the'occupancy of the detector track circuit containing the detector track relay DT by the illumination of the green lamp G or the red lamp R in the dispatchers office, a suitable code transmitter or automatical calling key CT is provided at this way station. This code transmitter is automatically controlled and is operated by the motor M, includes a code wheel comprising an occupied sector 0C and an unoccupied sector UC, a pick-up cam P0 a stop cam S0 and isolating cam 1C This code transmitter CT is operated in accordance with the conditions of the lockout or cut-out relay LE the coding stick relay CSR and the secondary lock relay SLR The manner in which these relays LE SLR and CSR may control the code transmitter GT and how these relays may prevent any other code transmitter being operated is most readily understood from the description of the operation of the system.

OPERATION Dispatchers control 0061' switch machines and signals Let us assume that there is an east bound (left to right) train moving in the single'track section N, and that the dispatcher wishes to clear the signal 8 to permit this train to enter the main track of the passing sidingPS In order to do so the dispatcher will move the lever L toward the right, and during the first part of the stroke of the lever will operate the canceling key CG thereby transmitting a code which will cause the normally closed contact 25 of the code responsive relay CRR to be momentarily opened.' Operation of the canceling code key CO causes the following circuit to be completed in interrupted fashion:-starting at the terminal B of a suitable battery, wire 26, back contact 21 of thesecondary lockout relay SLR in the dispatchers ofiic e, wire 28, indicating lamp 29, wires 3&3 and 3!, canceling key 0C wires 32, 33, 34 and 35, winding of the repeater code relay RCR and lockout relay LBS in multiple, to the terminal N connected to the other side of said battery.

It is obvious from the drawings that the relays RCR and LRS are connected in multiple in this same circuit. The lockout relay LRS is slow dropping as conventionally shown in the drawings, and this relay LRS keeps its contacts in the attracted position continuously in spite of the interrupted closure of thecircuit just traced. The

'repeatercode relay RCR however is quick acting v and causes its contacts 36 and 3'! to close in code simulate the proper code through the following circuit-beginning at the terminal B of a suitable battery, front contact 36 of relay RCR, wires 46, 4! and 42, front contact 43 of the lockout relay LRS, wire 44, back contact 45 of the secondary lockout relay SLR, coding wire WC, wire 4%, back contact 41 of the secondary lockout relay SLR wire 48, winding of the code responsive relay CRR wire 49 to the common return wire C, through front contact 3! of the repeater code relay RCR to the negative terminal N of the same battery. Ihis momentary opening of contact 25 of the code responsive relay CRR assures the de-energization of the relays NR. and RR in response to the transmission of the cancelling code.

If the lever L is continued through its movement to the right it engages the projection l5 on sector H) and operates the normal code key NC through its entire revolution, thereby transmitting a distinctive code to all of the various code responsive relays. This distinctive code will, however, only momentarily close the contact 50 of the code responsive relay CRR .Momentary closure of the contact 50 closes a pick-up circuit for the relay NR including the wires 5!, 52 and 53, thereby picking up the relay NR which thereafter is stuck up through the following circuit: beginning at the terminal B of a suitable battery normally closed contact 25 of the code responsive relay CRR wires 54 and 55, stick contact 56 of the relay NR wires 5! and 52, winding of the relay NR wire 53 to the negative terminal N of this battery.

With the normal relay NR in its energized condition current may flow to maintain the signal 9 clear through the following circuit:-beginning at the terminal B of a suitable battery,

wires 66 and El, back contact 62 of the reverse relay RR wires 63, front contacts 64 of the relay NR wires 65 and 66, contacts 61-68, wires 69 and i0, mechanism of the signal 6, wires H and i2, through a front and polar contact of a suitable home relay (not shown), to the negative terminal N connected to the other side of said battery. The flow of current in this circuit will maintain the signal 8 clear providing traffic conditions in advance thereof are and remain favorable. It should be noted that the energization of the relay NR did not eifect operation of the switch machine SM because this switch machine already assumes the normal straight track position. Had the switch machine SM assumed the reverse position it would havebeen operated to normal in a manner as explained in the applications of S. N. Wight above referred to.

In the same manner as normal relay NR may be caused to be energized and stuck up through a stick circuit, as just explained, the relay RR may also be controlled. If either of these relays are energized when the lever L is moved from the neutral position to either extreme positions the stick circuit for these relays NR and RR is momentarily broken so that these relays are lie-energized, and this is also true if the lever L is moved from one extreme position to the other extreme position. It may be pointed out here that the coding keys RC C0 and NC are preferably operated by the lever L through suitable time controlled mechanism, so that these keys are operated at the same rate of speed regardless of the speed at whichthe lever L itself is operated, this mechanism has for convenience been omitted from the drawings.

OS-ing the change in the condition of a track relay when the coding circuit is not in use The transmission of a signal indication to a dispatchers oflice to indicate the condition of occupancy of a certain track section, or other condition of traffic at a distant point, is known in railway signaling parlance as OS-ing. Let us now consider the transmission of an OS signal from the way station at the west end of the passing siding PS to the dispatchers ofiice. Let us assume that the train which formerly moved eastwardly in the single track section N is now entering the detector track circuit containing the track relay DT The entrance of the train in question on this detector track circuit causes the track relay DT to assume its ole-energized condition, thereby dropping its contacts 15 and i6. Dropping of contacts of this relay DT (conventionally shown by a dotted line) momentarily breaks the stick circuit for the coding stick relay CSR which stick circuit may be traced as follows:beginning at the terminal B of the suitable battery, front contacts l5 of the detector track relay DT wires l1 and 18, front stick contact 19 of the relay CSR wires 89 and 8!, winding of the relay CSR to the negative terminal N of this same battery. With the coding stick relay CSR deenergized the following circuit for the lockout relay LR, is completed:beginning at the terminal B, back contact 36 of the repeater code relay RCR (located in the tower), common return wire C, wire 82, non-inductive resistance 83, wire 84, back contact of the coding stick relay CSR wire 86, winding of the lockout relay LR wire 81, back contact 88 of the secondary lockout relay SLR wires 89, 96, back contacts 9| of the lookout relay LR wire 92, winding of the secondary lockout relay SLR wires 93 and LW, winding of thesecondary lockout relay SLR, wire 94, back contact 95 of the lockout relay LRS, wires 4| and 96, back contact 31 of the repeater coding relay RCR, to the negative terminal N of the same battery. The completion of the circuit justtraced energizes the lockout relay LR and also energizes the secondary lockout relays SLR and SLR.

It should be noted that the energizing of the secondary lockout relay SLR opens the circuit for the lookout relay LR so that no code can be transmitted from the east end of the passing siding PS. Also it should be noted that the energization of the secondary lockout relay SLR prevents the dispatcher from transmitting a code from the dispatchers office by manual operation of any one of the levers, this because the circuit over which such code would have to be transmitted is open at the back contacts 45 of the relay SLR. Also it should be noted that energization of the lockout relay LR by attraction of its front contact 9'! opens the-lockout circuit for all of the secondary lockout relays, such as the secondary lockout relays SLR located beyond the way station containing this lockout relay LR In other words, energization of the lockout relay LR prevents any other transmitter beyond the way station at which such lockout relay is located to function by reason of opening of the lockout circuit, and it prevents functioning of any code transmitter located between the dispatchers office and the way station at which such lockout relay is located by reason of the energization of the normally de-energized secondary lockout circuit for that portion.

With the coding stick relay CSR de-energized and the lookout relay LE energized the following circuit for energizing the motor M of the code transmitter CT is completed:beginning at the terminal B, front contact 98 of the lockout relay LE wires 99 and H00, back contacts ml of the coding stick relay CSRF, wire 32, contact Hit of isolating cam 1C wires HM and 195, armature of the motor M to the negative terminal N of said battery. With this circuit completed the motor M through suitable gearing not shown,

-wire Hi6 to the negative terminal N.

operates the coding wheel CW through a half revolution, for reasons preferably pointed out here-- inafter.

As soon as the shaft of the code transmitter CT has been operated through a comparatively small angle in a clockwise direction, as indicated by the arrow, the stick contact it? operated by the stop cam SC through the medium of the roller H78 closes an auxiliary stick circuit for the motor M as follows:beginning at the terminal B, contact ml, wires E09 and W5, armature of motor M The completion of this circuit assures that the code transmitter will be operated through the rest of its operating cycle, such cycle comprising a half revolution. With the code transmitter GT operating in the direction of the arrow, shown on motor M the coding circuit is intermittently closed to operate the master relay MR in the dispatchers office. This coding circuit may be traced as followsz-beginnirig at the battery 8 l5, located in the dispatchers oifice, wire lit, winding of the master relay MR, wire i ll, front contacts d5 of the secondary lockout relay SLR, which relay SLR is now energized, coding wire WC, wire l 59, through one of the various contacts of thecoding sector 00, wire I20, common return wire C, wire i 2 l back to the battery H5.

This intermittent completion of the circuit just traced causes the master relay MR to operate in' code like fashion and in turn through the following circuit affects all of the various code responsive relays CRRfi, CRR CERF, ORR", etc. located in the towerz-beginning at the terminal B, wire E23, front contact 524i of the master relay MR, wire i255 through the various coding relays in multiple, wire E26, front contacts 52? of sec-- ondary lockout relay SLR, wire E28, front contacts I29 of the master relay MR, wire 36 to the negative terminal N of the same battery. With the particular code transmitted by the code sector 0C (signifying occupied) the code responsive selector relay (335th: momentarily closes its normally open contacts lSi thereby completing the following pick-up circuit for the red indicating relay RI :beginning at the terminal B, contact '13! of the code responsive relay CRE wires E32 and its, winding of the red indicating relay R1 to the negative terminal N. With the pick-up circuit for the relay R1 momentarily closed this relay assumes its energized condition and closes the following stick circuit:- beginning at the'terminal B, normally closed contacts iSl of the code responsive relays CRE wire l35, frontstick contact I36 of the relayRP, wires l3? and I53, winding of the relay R1 to the negative terminal N. With this relay R1 energized the red lamp R is energized through a circuit including the front contact 538 of the relay R1 When the code transmitter CT has almost completed its coding cycle of half a revolution the following pick-up circuit for the coding stick relay CSR is completed providing the detector track relay DT has not in the mean time been reenergized:beginning at the terminal B, front contacts 98 of the lookout relay LR wires 99 and HG, back contacts "it of the detector track relay DT wire Hi, cam operated contact H2, assuming its right hand position, wires H3 and 8!, winding of the coding stick relay CSR to the negative terminal N of said battery.

It should be noted if it were not for the isolating contact it this relay CSR might possibly be picked up too early, and irrespective of whether or not relay LR is up, by energy fed from B through contact ital. With this pick-up circuit momentarily completed the coding stick relay CSR is picked up, after which it is stuck up throughits stick circuit heretofore traced with the contact E5 of the detector track relay DT in its retracted position. With the coding stick relay CSR again in its energized condition the first traced circuit for the motor M is broken at the contacts lill of this relay CSR and the lockout relay LE is again de-energized because its energizing circuit is broken in the contacts of this relay CSR It or course appears that with the lookout relay LR again in its normal condition the lockout function is no longer effective and any of the other code transmitters may be automatically operated to transmit a particular code to thedispatchers ofilce.

Let us now assume that the train in question again moves oil of the detector track circuit, bearing in mind that the code transmitter has only been operated through a half revolution in response to de--energization of the track relay DT With the detector track relay DT now moved to its attracted position the stick circuit of coding stick .relay CSR is again momentarily broken, and this relay is again deenergized, thus causing the lookout relay LR to be picked up and the code transmitter CT to be operated through the second half of the revolution of the code transmitter GT This operation is exactly the same as that heretofore described except that the contact H2 is moved to the left instead of the right, to complete a pick-up circuit for the reiay GER at the end of this cycle (second half revolution) and that a diiferent and distinctive code is transmitted to the dispatchers office, which'causcs the code responsive relay CPR to momentarily open its contact i3 3 and to momentarily close its contact 63% thereby cancelling the red lamp R and picking up the stick relay G1 and lamp G The code for manifesting unoccupancy of the detector track section containing track relay DT as just explained is transmitted through the coding sector UC (signifying unoccupancy) in a manner as already explained in connection with coding sector 06. These two codes are distinctive as conventionally shown by the sectors 00 and UC. In this connection it is desired to pointout that the code responsive relay CRR and CR5, are preferably such as shown in the patent to Field 1,343,256 granted June 15, 1,920 and may be combined into a single unit having one normally closed contact and two normally opened contacts, which contacts are actuated in response to distinctive codes.

OS-z'ng the change in the condition of a detector track relay when the coding circuit is in use From the description of the operation just given it is of course apparent that the lockout relay LR must be energized in order to start the code transmitter C'I' into operation, this by reason of the fact that the motor M cannot be started unless the contacts 93 of the lockout relay LR. are closed. Also it should be noted that when a lookout relay LP, is energized that the associated secondary lockout relay SLR; cannot be energized. Further, that with relay PR energized all of the secondary lockout relays toward the dispatchers 'ofiice are in their energized condition and thereby prevent their associated lockout relays LR. etc. from becoming energized thereafter; and that with the lookout relay LE in its energized condition, all of the lookout relays more remote from the dispatchers oifice cannot be energized thereafter because the lockout circuit is broken at the back contacts 91 of the lookout relay LR In other words, it is impossible for any other lockout relay LE LE etc. to assume an energized condition if a particular lockout relay such as LR assumes its energized condition. Putting it another way, only one lockout relay can be energized at one timeand for this reason only one code transmitter can be operated at one time. Not only if a particular lockout relay is energized does it look out all of the other code transmitters, but the secondary lockout relay SLR in the .tower is also energized and prevents the dispatcher from transmitting a code to a way station by operating one of his levers. is again directed to the indicating lamps .24 and 29, of which the lamp 29 flickers in code-like fashion inresponse to manual operation of a lever and the transmission of a code, and of which the indicating lamp 24 is energized when 'a code is received from a distant way station for which reason the dispatcher should not operate a lever.

OS-ing in the event that two difierent track circuits are occupied or! unoccupied at exactly the same instant I Let us assume, for instance, that there is an east bound train in the single track section N and that there is a westbound train in the single track'section O, and that these trains pass the signals 8 and I respectively at exactly the same instant. This simultaneous occupancy of the two detector track circuits would of course causeboth of the coding stick relays CSR and CSR. to be deenergized, thereby closing their back contacts .and 85 The closure of contact 85 of relay CSR would complete an energizing circuit for the lookout relay LR and the closure of the contact 85 of the relay .CSR would close an energizing circuit for the lookout relay LE Both of the relays LE and LE will move toward their attracted position and if the relay LR should open its contact 91 before the relay .SLR (connected in series with relay LE opens its contact 88 the relay LR, would prevail and the code transmitter CT be operated and the transmitter GT locked out. Should, however, the contact 88 of relay SLR open first and contact 91 of relay LR open immediately thereafter there might possibly be a bobbing back and forth between relays SLR LR SLR and LR, until one or the other way stations would look out the other. In other words if two lockout relays are In this connection attention energized simultaneously each of these relays will try to open the energizing circuit of the other relay. That is, the lookout relays are so interlocked that the energization of one lockout relay will result in opening the energizing circuit for the other lockout relay, and if there are a plurality of lockout relays energized simultaneously these various lockout relays will fight, so to speak, that is will repeatedly :assume the attracted and retracted position until vone of these lookout relays has obtained a predominating advantage over the other lockout relay and has succeeded in opening the circuits of such other lockout relay, and may therefore remain in its energized condition. The various lockout relays and the code transmitters are so designed and have operating characteristics so that a transmitter cannot get under way while the fight between lockout relays continues. As soon as one .of the lookout relays has won out, so to speak, its corresponding code transmitter is set into operation and causes its particular node to be transmitted. It should be noted that the various resistance units 83 associated with the circuits for the various lockout relays become .smaller in the direction from the .dispatchers oiiice DO. fl'helresistances of these various units are so selected that the lookout relays and secondary lockout relays will function properly regardless of the number of these relays that are connected inseries, that .is, regardless of the distance of the particular way station at which a lookout relay is energized. If desired, these resistance units .83 may be so selectedthat certain lockout relays have an advantage over other lockout relays, so that if a fight for the coding circuit should take place .certain selected lockout relays would soon effectively lock out all other lockout relays.

Applicant has devised a circuit arrangement in which telephone selectors of commercial or special construction are .co-ordinated with manually operated calling keys and automatically controlled calling keys, or code. transmitters, .so to enable .a large number of. switch machines .and signals to be controlled and a large number of distinctive indications to be transmitted to the dispatcher over the same. control circuit. The present invention which has been illustrated by a single embodiment whereof only, also includes a lookout circuit arrangement whereby it is fimpossible for more than twoautomatically operated code transmitters to transmit impulses over the coding circuit at a particular time. Not only does this interlocking or lockout arrangement prevent two codes being transmitted automatically simultaneously if the second code is started after the first has been partially transmitted, but the arrangement proposed does not allow the transmission of two different codes to be even started at the same time. That is, if two way stations are simultaneously conditioned to transmit .distinctive codes to the dispatchers ofiice, both of these way station code transmitters are locked out until it has been determined which of the two shall be permitted to transmit its particular distinctive code to the Way station. These features are decidedly essential and important by reason of the fact that the transmission 'of 'two codes at the same time may actually give a false indication. Also, in addition to the lookout features which prevent two codes being transmitted to the tower automatically at the same time, provision has been made to prevent the dispatcher transmitting a code if the code circuit is already in use, this being accomplished. by the secondary lockout relay, SLR located in the dispatchers oflice or tower DO. Although the telephone selector or code responsive relays CRR. are preferably of the construction disclosed in the Field patent, above referred to, these selectors may be constructed as disclosed in the patent to Gear et all. No. 1,118,120 dated Nov. 24, 1914.

Having thus shown only one rather specific embodiment of my invention, it should be under: stood that this has been done for the purpose of facilitating the illustration and description thereof, and the particular embodiment shown and described has not been selected for the purpose of illustrating the scope of the invention or the exact construction preferably employed in practicing the invention, and it is to be understood that various changes, modifications, and additions may be made to adapt the invention to the particular installation and track layout to which the invention is to be applied, all without departing from the spirit and scope of the invention and the idea of means underlying the same except as demanded by the scope of the appended claims.

What I claim is: 1 A train dispatching system of the type in which information is transmitted to the engineer of a "moving train by distinctive codes transmitted from a dispatchers office and in which indications are transmitted to the dispatchers ofiice comprising, code-responsive means in the dispatchers office closing one contact and opening another contact upon the reception of a particular code, and closing a third contact and opening a fourth contact upon the reception of another distinctive code, two stick relays associated with said code-responsive means one of which is picked up in response to momentary closure of said one contact and which has its stick circuit opened upon and only upon the opening of said fourth contact and the other of said stick relays of which has its pick-up circuit closed upon closure of the third contact and has its stick circuit broken upon and only upon the opening of said another contact, and code-transmitting means located at a distant way station for transmitting such particular code and such another distinctive code.

2. A train dispatching system of the type in which information is transmitted to the engineer of a moving train by distinctive codes transmitted from a dispatchers oflice and in which indications are automatically transmitted to the dispatchers office comprising, code-responsive means in the dispatchers oflice momentarily closing one contact and opening another contact upon the reception of a particular code, and closing a third contact and opening a fourth contactupon the reception of another distinctive code, two stick relays associated with said code-responsive means one of which is picked up in response to momentary closure of said one contact and which has its stick circuit opened upon and only upon the opening of said fourth contact, and the other of said stick relays has its pick-up circuit closed upon closure of said third contact and has its stick circuit broken upon and only upon the opening of said another contact, indicating means in the dispatchers ofiice controlled by said stick relays, and means at a distant way station for transmitting such particular code and such another distinctive code to the dispatchers office.

3. An automatically-operated code transmitter for indicating the condition of a relay controlled in accordance with traffic conditions; a normally energized stick relay for controlling said code transmitter; and means including such stick relay for operating said code transmitter through a half cycle if said traiflc controlled relay is changed from one condition to another condition, and operating said code transmitter through an entire cycle if said traffic controlled relay is changed from one condition to another and then is immediately changed back to said one condi tion.

4. In a dispatching system of the code-responsive type, the combination with a dispatchers oflice and a plurality of way stations, a single line circuit connecting said dispatchers office with all of said way stations, code-responsive selector means at each way station each distinctively responsive to a particular code transmitted from the dispatchers ofiice, and a lever in the dispatchers oihce having code transmitting means associated therewith, which will transmit one particular code when moved from an intermediate position to an extreme position, will transmit another particular code when moved from an intermediate position to another extreme position, will transmit no code when moved from either extreme position to the corresponding respective intermediate position, and will transmit a third distinctive code when moved from one to the other of said intermediate positions, said particular codes being capable of operating certain of said code-responsive devices.

5. In combination, a distant way station, a local oifice, a trafiic controlling device at said way station, apparatus comprising code creating and code responsive apparatus for transmitting to said oflice a change in the condition of said traffic controlling device, a change storing relay normally assuming a certain condition which if changed manifests that an indication of a change of said traffic controlling device must be transmitted to said office, means for actuating said change storing relay upon a change in said traffic controlling device, a contact reflecting the condition of said trafiic controlling device, another contact reflecting the last code transmitted to' controlling device, a change storing relay normally assuming a certain condition which if changed initiates said apparatus to transmit an indication of a change of said traffic controlling device to said office, means for actuating said change storing relay upon a change in said trafiic controlling device, a contact reflecting the condition of said trafiic controlling device, another contact reflecting the last code transmitted to said ofiice, and means to maintain said appara tus in operation to transmit a cancelling code, in the event said trafiic controlling device is changed to a new condition and is then returned to its previous condition before an indication of said new condition was transmitted, including a circuit manifesting the condition of correspondence of said contact and said another contact.

'7. In combination, a local oflice, a distant station, a normally energized track relay which when deenergized manifests the presence of a train in a track section, selector apparatus for transmitting by an occupied or unoccupied code the con-, dition of said track relay, a change storing relay normally assuming a certain condition which if changed initiates said apparatus into operation and which is changed when said track relay assumes a new condition, and means manifesting at said station the last of said two codes which was transmitted by said apparatus for returning said change storing relay to normal.

8. A train dispatching system of the type in which the information is transmitted to the engineerof a moving train by distinctive codes transmitted from a dispatchersofiice and in which indications are automatically transmitted to the dispatchers office comp-rising, code-responsive means in the dispatchers office closing one contact and opening another contact upon the reception of a particular code, and closing a third contact and opening a fourth contact upon the reception of another distinctive code, two stick relays associated with said code-responsive means one of which is picked up in response to momentary closure of said one contact and which has its stick circuit opened upon the opening of said fourth contact, and the other of said stick relays has its pick-up circuit closed upon closure of said third contact and has its stick circuit broken upon the opening of said another contact, indicating means in the dispatchers office controlled by said stick relays, and means at a distant way station for transmitting such particular code and such another distinctive code to the dispatchers oflice.

9. A train dispatching system of the type in which the information is transmitted to the engineer of a moving train by distinctive codes transmitted from a dispatchers oifice comprising, code-responsive means closing one contact and opening another contact upon the reception of a particular code, and closing a third contact and opening a fourth contact upon the reception of another distinctive code, two stick relays associated with said code-responsive means one of which is picked up in response to momentary closure of said one contact and which has its stick circuit opened upon the opening of said fourth contact and the other of said stick relays has its pick-up circuit closed upon closure of the third contact and has its stick circuit broken upon the opening of said another contact, and code-transmitting means located at a distant point for transmitting such particular code and such another distinctive code.

10. A train dispatching system of the type in which the information is transmitted to the engineer of a moving train by distinctive codes transmitted from a dispatchers oflice comprising, code-responsive means closing one contact and opening another contact upon the reception of a particular code, and closing a third contact and opening a fourth contact upon the reception of another distinctive code, two stick relays associated with said code-responsive means one of which is picked up in response to momentary closure of said one contact and which has its stick circuit opened upon the opening of said fourth contact, and the other of said stick relays has its pick-up circuit closed upon closure of said third contact and has its stick circuit broken upon the opening of said another contact, indicating means controlled by said stick relays, and means at a distant point for transmitting such particular code and such another distinctive code.

11. In a centralized traffic controlling system of the code, the combination with a central office and a plurality of field stations, of code transmitting means for transmitting through the medium of distinctive codes conditions of traffic from a distant field station to said central ofiice, a stick relay at such field station, means for picking up said stick relay only upon the transmission from such field station to said central ofiice of a multiple impulse code identifying the condition of traiTic then existing, means for dropping said stick relay upon a change of traffi'c conditions at such field station, and a circuit for controlling said code transmitting means controlled by said stick relay.

12. In a centralized traffic controlling system of the code type; the combination with a central oflice and a plurality of field stations; of code transmitting means for transmitting through the medium of distinctive codes, each comprising a plurality of impulses, conditions of trafiic from a distant field station to said central ofiice; a contact reflecting traffic conditions at each field station; a normally energized starting relay at each field station having a stick circuit including said contact for that station and momentarily broken when said contact is moved from one traffic reflecting condition to another trafiic reflecting condition; a circuit for initiating said code transmitting means controlled by said starting relay; and a pick-up circuit for said starting relay closed only when said code transmitting means has transmitted a code corresponding to the position then assumed by said contact. v

13. In a centralized trafiic controlling system of the code type; the combination with a central ofl'lce and a plurality of field stations; of code transmitting means for transmitting through the medium of distinctive codes, each comprising a plurality of impulses, conditions of trafiic from a distant field station to said central oflice; a contact reflecting trafiic conditions at each field station; a normally energized starting relay at each field station having a stick circuit including said contact for that station and momentarily broken when said contact is moved from one trafiic reflecting condition to another traific reflecting condition; a circuit for initiating said code transmitting means controlled by said starting relay; a second circuit for continuing operation of said code transmitting means closed upon initiation of said code transmitting means and opened when a complete code has been transmitted; and a pick-up circuit for said starting relay closed during operation of said code transmitting means only if the code transmitted corresponds to the position then assumed by said contact.

14. In a centralized railway trafiic controlling system of the code type, the combination with a central omce and a plurality of field stations, a circuit including a line wire and a common wire extending from said office to the first field station and from station to station, code transmitting means at each of said field stations for transmitting to said office a series of impulses characterizing a code, a second line wire extending from said oifice to said first station and from station to station, a railway traffic device reflecting at each station the condition of traific which is to be indicated, a first relay at each station changed from one condition to another upon a change in the condition of said device for that station and changed only from said another to said one condition upon transmission of a code iii by the associated code transmitting means, a

second relay which if energized disconnects said second line wire from more remote stations and energized from a source at said ofiice and over said second line wire when said first relay assumes said another condition, and a circuit for rendering said code transmitting means active controlled by said second relay.

15. In a centralized railway traiiic controlling system of the code type, the combination with a central office and a plurality of field stations, a circuit including a line wire and a common wire extending from said office to the first field station and from station to station, code transmitting means at each of said field stations for transmitting to said office a series of impulses characterizing a code, a second line wire extending from said office to said first station and from station to station, a railway traffic device refleeting at each station the condition of traific which is to be indicated, a stick relay at each station having a stick circuit including a contact momentarily opened upon a change in the condition of said device for that station and having a pick-up circuit closed upon transmission of a code by the associated code transmitting means, a second relay which if energized disconnects said second line wire from more remote stations and energized from a source at said office and over said second line wire when said first relay assumes its deenergized condition, and a circuit for rendering said code transmitting means active controlled by said second relay.

16. In a centralized trafi'ic controlling system of the code type, the combination with a central oiiice and a field station; of code transmitting means at said field station for transmitting through the medium of distinctive codes, each comprising a plurality of impulses, conditions of traffic from said field station to said ofiice; a track relay at said field station; a normally energized stick relay at said field station having a stick circuit including front and back contacts of said track relay in multiple, whereby a change in the condition of said track relay deenergizes said stick relay; a circuit for initiating said code transmitting means controlled by said stick relay to cause said code transmitting means to transmit a code corresponding to the condition then assumed by said track relay; and a pick-up circuit for said stick relay closed only when said code transmitting means has transmitted a code corresponding to the condition then assumed by said track relay.

FRANK BENEDICT. 

